Turbidity Sensor Noise Model for Single-Beam Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing turbidity measurement methods using single-beam sensors are affected by interference variables such as reflections from walls and contamination on optical windows, leading to inaccurate readings, especially at low turbidity levels, and current compensation methods require multiple light sources or detectors, which are not feasible for all applications.
Innovation Solution
A method that involves detecting the chronological sequence of scattered light intensity, determining a mean value, and using calibration and noise models to correct for interference, allowing for reliable turbidity measurement even with single-beam sensors by distinguishing between turbidity-related and interference signals through noise analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-beam sensor is used for turbidity measurement, then the device complexity is reduced and it complies with regulations, but measurement precision deteriorates due to interference from reflections and window contamination
Solution Approach 1:
The patent converts the harmful interference signals (reflections and contamination effects) into useful information by analyzing their statistical noise characteristics. By evaluating the noise properties of the measured signal, the system distinguishes between genuine turbidity-related scattering and interference signals, thereby maintaining measurement precision while using a simple single-beam sensor structure
Solution Approach 2:
The system implements a feedback mechanism where the measured scattered light intensity is continuously evaluated for its noise characteristics. This feedback loop allows the system to identify interference patterns and compensate for them, improving measurement accuracy without requiring additional hardware components
2Measurement precision
If model-based diagnosis or multi-beam alternating light methods are used to compensate for interference, then measurement precision improves, but device complexity increases and compliance with single-beam regulations is lost
Solution Approach 1:
The patent replaces the mechanical/optical complexity of multi-beam systems with a signal processing approach. Instead of using multiple physical light sources and detectors, the system uses statistical noise analysis and evaluation of the chronological sequence of scattered light intensity to achieve interference compensation, thereby maintaining compliance with single-beam regulations
3Manufacturing precision
If light scattering is measured at very low turbidity levels, then the sensor can detect low concentrations, but measurement reliability deteriorates due to dominant interference signals from reflections and wall scattering
Solution Approach 1:
The patent converts the dominant interference signals that normally degrade low-turbidity measurements into useful information. By analyzing the statistical noise characteristics of the measured signal, the system identifies and compensates for interference patterns, enabling reliable detection at very low turbidity levels where interference would normally dominate
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables accurate and reliable turbidity measurement by compensating for noise and interference, improving measurement reliability and reducing maintenance requirements for turbidity sensors, even in restricted spaces or low turbidity conditions.
Implementation Method 1
Any light striking particles suspended in a liquid is scattered
Implementation Method 2
The measured scattered light intensity can be substantially negatively affected... if these reflection and/or scattered signals that are not caused by suspended particles are detected by the sensor
Data Source
AI summary
A method for determining a turbidity of a medium in a container using at least one turbidity sensor. Depending on the ambient conditions at the installation location of the turbidity sensor, comprising the following steps: passing transmitted radiation through the medium, wherein the transmitted radiation is converted by interaction with the medium, as a function of the turbidity in the received radiation; receiving the received radiation; converting the received radiation into a scattered light intensity, and determining the turbidity from the scattered light intensity. The method is characterized by the following steps: detecting the chronological sequence of the scattered light intensity; determining a mean value on the basis of the chronological sequence of the scattered light intensity; determining the turbidity from the mean value using a calibration model by assigning a turbidity to each mean value; determining a corrected mean value on the basis of the chronological sequence of the scattered light intensity, by determining a noise parameter from the scattered light intensity, and by determining the corrected mean value from the noise parameter using a noise model, and determining a corrected turbidity at least from the corrected mean value using the calibration model by assigning a corrected turbidity to each corrected mean value. The invention further relates to a turbidity sensor for implementing the method.